Power receiving apparatus, control method of power receiving apparatus, and storage medium

ABSTRACT

A power receiving apparatus includes a power receiving unit configured to wirelessly receive power from a power transmission apparatus, a communication unit configured to perform communication based on a standard of Near Field Communication (NFC), a detection unit configured to detect the power transmission apparatus, and a control unit configured to control the communication unit not to perform the communication based on the standard of NFC based on detection of the power transmission apparatus by the detection unit, wherein the power receiving unit receives power after the control unit controls the communication unit not to perform communication based on the standard of NFC.

BACKGROUND Field of the Disclosure

The present disclosure relates to a power receiving apparatus, a controlmethod of a power receiving apparatus, and a storage medium.

Description of the Related Art

In recent years, the technological development of wireless powertransmission systems such as a wireless charging system has been widelyconducted. Japanese Patent Application Laid-Open No. 2016-007116discusses a power transmission apparatus and a power receiving apparatusthat are compliant with a standard (hereinafter, referred to as a “WPCstandard”) stipulated by a Wireless Power Consortium (WPC), which is agroup for developing standards of wireless charging.

A Near Field Communication (NFC) method is one type of a wirelesscommunication method. In addition, a standard (specification) stipulatedby the NFC forum defines a card emulation mode in which a battery-drivenNFC module emulates an NFC tag or an NFC card (hereinafter, collectivelyreferred to as an “NFC tag”). Moreover, the NFC forum also defines areader/writer mode for reading an NFC tag and a peer-to-peer mode fordirectly exchanging messages between NFC devices. Among power receivingapparatuses such as smartphones that are compliant with the WPCstandard, some power receiving apparatuses include an NFC moduleoperating in these modes, and perform communication based on thestandard of NFC.

An NFC tag does not include a battery and is driven using energy ofelectromagnetic wave transmitted from a communication partner incommunication. If the above-described power transmission apparatuswirelessly transmits high power to this NFC tag, an antenna elementincluded in the NFC tag can possibly be damaged. It can be consideredthat, for avoiding such a situation, the power transmission apparatusrestricts power transmission when the power transmission apparatusdetects an object performing communication based on the standard of NFC.Nevertheless, in such a configuration, the following issues aregenerated. More specifically, when the power transmission apparatusdetects an object performing communication based on the standard of NFC,the power transmission apparatus is considered to restrict powertransmission irrespective of whether the object is an NFC tag or a powerreceiving apparatus performing communication based on the standard ofNFC. Thus, if power transmission to a power receiving apparatusperforming communication based on the standard of NFC is restricted, theamount of received power may be insufficient.

SUMMARY

Some embodiments are directed to enabling a power receiving apparatusthat performs communication based on a standard of NFC to appropriatelyreceive power.

According an aspect of some embodiments, a power receiving apparatusincludes a power receiving unit configured to wirelessly receive powerfrom a power transmission apparatus, a communication unit configured toperform communication based on a standard of Near Field Communication(NFC), a detection unit configured to detect the power transmissionapparatus, and a control unit configured to control the communicationunit not to perform the communication based on the standard of NFC basedon detection of the power transmission apparatus by the detection unit,wherein the power receiving unit receives power after the control unitcontrols the communication unit not to perform communication based onthe standard of NFC.

Further features of various embodiments will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a configuration example of a wirelesscharging system.

FIG. 2 is a functional block diagram illustrating a configurationexample of a power receiving apparatus according to a first exemplaryembodiment.

FIG. 3 is a functional block diagram illustrating a configurationexample of a power transmission apparatus according to the firstexemplary embodiment.

FIG. 4 is a diagram illustrating an operation sequence of a wirelesscharging system according to the first exemplary embodiment.

FIG. 5, consisting of FIGS. 5A and 5B, is a flowchart illustrating anoperation of the power receiving apparatus according to the firstexemplary embodiment.

FIG. 6 is a diagram illustrating an operation sequence of a wirelesscharging system according to a second exemplary embodiment.

FIG. 7, consisting of FIGS. 7A and 7B, is a flowchart illustrating anoperation of a power receiving apparatus according to the secondexemplary embodiment.

FIG. 8 is a flowchart illustrating an operation of each of a powertransmission apparatus according to the first exemplary embodiment and apower transmission apparatus according to the second exemplaryembodiment.

FIG. 9 is a diagram illustrating an operation sequence of a wirelesscharging system according to a third exemplary embodiment.

FIG. 10, consisting of FIGS. 10A and 10B, is a flowchart illustrating anoperation of a power receiving apparatus according to the thirdexemplary embodiment.

FIG. 11 is a flowchart illustrating an operation of a power transmissionapparatus according to the third exemplary embodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, exemplary embodiments will be described in detail withreference to the drawings. The following exemplary embodiments are mereexamples and are not intended to limit the scope of all embodiments tothe configurations and methods described in the exemplary embodiments.

(Configuration of System)

Hereinafter, a first exemplary embodiment will be described. FIG. 1illustrates a configuration example of a wireless charging system(wireless power transmission system) according to the present exemplaryembodiment. The system includes a power receiving apparatus 101 and apower transmission apparatus 102. Hereinafter, a power receivingapparatus will be referred to as an RX and a power transmissionapparatus will be referred to as a TX. The RX 101 and the TX 102 arecompliant with a Wireless Power Consortium (WPC) standard. The RX 101receives power from the TX 102 and enables a battery to be charged. TheTX 102 is an electronic device that wirelessly transmits power to the RX101 placed on a charging stand of the TX 102. Hereinafter, thedescription will be given using an example case where the RX 101 isplaced on the charging stand. Nevertheless, when the TX 102 transmitspower to the RX 101, the RX 101 only needs to exist within a powertransmittable range (operating volume) of the TX 102 and may not need tobe placed on the charging stand.

The RX 101 and the TX 102 can include a function of executing anapplication other than wireless charging. As an example, the RX 101 is asmartphone and the TX 102 is an accessory device for charging thesmartphone. The RX 101 and the TX 102 may be storage devices, such ashard disc devices or memory devices, or may be an information processingapparatus, such as a personal computer (PC). Alternatively, the RX 101and the TX 102 may be imaging apparatuses (camera, video camera, etc.),for example. The RX 101 and the TX 102 may be image input apparatuses,such as scanners, or may be image output apparatuses, such as printers,copiers, or projectors. Also, the TX 102 may be a smartphone. In thiscase, the RX 101 may be another smartphone, or may be a wirelessearphone. Then, the RX 101 may be an automobile. Furthermore, the TX 102may be a charger which is set on a console or the like in an automobile.

The RX 101 is equipped with a Near Field Communication (hereinafter,referred to as “NFC”) function, and can read an NFC tag or performelectronic money payment, for example, using the function. The TX 102 isalso equipped with the NFC function for reading an NFC tag. The TX 102can detect an NFC tag by performing communication based on a standard ofNFC. Furthermore, the TX 102 can stop or restrict power transmissionprocessing based on the detection result to protect an NFC tag.

The system performs wireless power transmission using an electromagneticinduction method for wireless charging, based on the WPC standard. Forexample, the RX 101 and the TX 102 perform wireless power transmissionfor wireless charging that is based on the WPC standard, between a powerreceiving antenna of the RX 101 and a power transmission antenna of theTX 102. In addition, a wireless power transmission method applied to thesystem is not limited to a method defined by the WPC standard, and maybe an electromagnetic induction method, a magnetic field resonancemethod, an electric field resonance method, a microwave method, or amethod using a laser. In the present exemplary embodiment, wirelesspower transmission is used for wireless charging, but wireless powertransmission may be performed for purposes other than wireless charging.

In the WPC standard, the magnitude of power that can be guaranteed whenthe RX 101 receives power from the TX 102 is defined by a value ofguaranteed power (hereinafter, referred to as “GP”). The value of GPindicates a value of power guaranteed to be output to a load in the RX101 (e.g., charging circuit, etc.) even if a positional relationshipbetween the RX 101 and the TX 102 varies and power transmissionefficiency between the power receiving antenna and the powertransmission antenna declines, for example. When the value of GPindicates 5 watts, for example, the TX 102 performs power transmissionwhile controlling power such that power of 5 watts can be output to theload in the RX 101 even if a positional relationship between the powerreceiving antenna and the power transmission antenna varies and powertransmission efficiency declines.

The RX 101 and the TX 102 according to the present exemplary embodimentperform communication for power transmission and reception control thatis based on the WPC standard. The WPC standard defines a plurality ofphases including a Power Transfer Phase in which power transfer isexecuted, and phases preceding actual power transfer, and communicationfor power transmission and reception control required in each phase isperformed. The phases preceding power transfer include a SelectionPhase, a Ping Phase, an Identification and Configuration Phase, aNegotiation Phase, and a Calibration Phase. Hereinafter, theIdentification and Configuration Phase will be referred to as an I&CPhase.

In the Selection Phase, the TX 102 intermittently transmits an AnalogPing, and detects that an object is placed on the charging stand of theTX 102 (e.g., the RX 101 or a conductor strip is placed on the chargingstand). The TX 102 detects at least either one of a voltage value and acurrent value of the power transmission antenna that are obtainable whenthe Analog Ping is transmitted, determines that an object exists if thevoltage value falls below a certain threshold or if the current valueexceeds a certain threshold, and shifts to the Ping Phase.

In the Ping Phase, the TX 102 transmits a Digital Ping having largerpower than the Analog Ping. The Digital Ping has power large enough foractivating a control unit of the RX 101 placed on a charging stand. TheRX 101 notifies the magnitude of received voltage to the TX 102. In thismanner, by receiving a response from the RX 101 that has received theDigital Ping, the TX 102 recognizes that the object detected in theSelection Phase is the RX 101. If the TX 102 receives the notificationof a received voltage value, the TX 102 shifts to the I&C Phase.

In the I&C Phase, the TX 102 identifies the RX 101 and acquires deviceconfiguration information (capability information) from the RX 101.Thus, the RX 101 transmits an ID Packet and a Configuration Packet tothe TX 102. The ID Packet includes identification information of the RX101 and the Configuration Packet includes device configurationinformation (capability information) of the RX 101. The TX 102 that hasreceived the ID Packet and the Configuration Packet returns anacknowledge (ACK) as a response. Then, the I&C Phase is ended.

In the Negotiation Phase, a value of GP is determined based on a valueof GP required by the RX 101 or power transmission capability of the TX102.

In the Calibration Phase, the RX 101 notifies a received power value tothe TX 102 and the TX 102 performs adjustment for efficientlytransmitting power, based on the WPC standard.

In the Power Transfer Phase, control for a start or continuation ofpower transmission and for a stop of power transmission caused due to anerror or full charge is performed.

For the above-described power transmission and reception control, the TX102 and the RX 101 perform communication (hereinafter, referred to as“first communication”) for superimposing a signal on electromagneticwaves transmitted from an antenna, using the same antenna (coil) as thatfor wireless power transmission, based on the WPC standard. A range inwhich the first communication that is based on the WPC standard can beperformed between the TX 102 and the RX 101 is substantially similar toa power transmissible range in which the TX 102 can transmit power.

To perform the above-described power transmission and reception control,the TX 102 and the RX 101 may perform communication (hereinafter,referred to as “second communication”) using an antenna and a frequencythat are different from those for wireless power transmission. Forexample, a frequency band of electromagnetic waves used in the secondcommunication is higher than a frequency band of electromagnetic wavesused in the first communication. In this case, by using the secondcommunication, it is possible to perform higher-speed communication thanthat performed in the case of using the first communication.

Examples of the second communication include a communication method thatis compliant with a Bluetooth 0 Low Energy (hereinafter, referred to as“BLE”) standard. In this case, the TX 102 operates as a Peripheral inthe BLE standard and the RX 101 operates as a Central in the BLEstandard, but these roles according to the BLE standard may be reversed.In addition, the second communication may be performed in compliancewith another communication method, such as a wireless local area network(LAN) (e.g., Wi-Fi®) of the IEEE802.11 standard series or ZigBee. Whenthe TX 102 can perform the second communication and the RX 101 exists inthe power transmissible range, the RX 101 and the TX 102 can exchangeinformation by the second communication.

(Apparatus Configuration)

Subsequently, configurations of the power receiving apparatus 101 (theRX 101) and the power transmission apparatus 102 (the TX 102) accordingto the present exemplary embodiment will be described. Theconfigurations to be described below are mere examples, and a part (orall depending on the case) of the configurations to be described may beomitted or substituted with another configuration having another similarfunction, or yet another configuration may be added to theconfigurations to be described. Furthermore, one block to be describedbelow may be divided into a plurality of blocks or a plurality of blocksmay be merged into one block.

FIG. 2 is a functional block diagram illustrating a configurationexample of the RX 101 according to the present exemplary embodiment. Thefollowing description will be given using a smartphone as an example ofthe RX 101, but the RX 101 according to the present exemplary embodimentis not limited to this.

The RX 101 includes a control unit 201, a power source unit 202, a powerreceiving antenna 203, a smartphone function processing unit 204, a WPCcommunication unit 205, a storage unit 206, a power receiving unit 207,a charging unit 208, a battery 209, and an NFC unit 210. In addition, aplurality of functional blocks illustrated in FIG. 2 may be implementedas one hardware module.

The control unit 201 controls the entire smartphone (i.e., the RX 101)by executing a control program stored in the storage unit 206, forexample. In other words, the control unit 201 controls each functionalunit illustrated in FIG. 2. Furthermore, the control unit 201 mayperform control for executing an application other than wireless powertransmission. As an example, the control unit 201 includes one or moreprocessors, such as a central processing unit (CPU) or a microprocessorunit (MPU). In addition, the entire smartphone may be controlled bycooperation with an operating system (OS) executed by the control unit201.

In addition, the control unit 201 may include hardware dedicated forspecific processing, such as an application specific integrated circuit(ASIC). In addition, the control unit 201 may include an array circuit,such as a field programmable gate array (FPGA) compiled so as to executepredetermined processing. The control unit 201 causes the storage unit206 to store information to be stored during the execution of varioustypes of processing. In addition, the control unit 201 can measure timeusing a timer (not illustrated).

The power source unit 202 supplies power to each functional block inconjunction with the charging unit 208 and the battery 209. Thesmartphone function processing unit 204 includes those functionsnormally included in a smartphone, such as a user interface (UI), aphone call unit, and an internet processing unit. The descriptions ofthese functions will be omitted.

The WPC communication unit 205 performs the above-describedcommunication for power reception control that is based on the WPCstandard, with a communication unit included in the TX 102. The WPCcommunication unit 205 acquires information transmitted from the TX 102by demodulating electromagnetic waves input from the power receivingantenna 203, and performs the first communication with the TX 102 bysuperimposing, on electromagnetic waves, information to be transmittedto the TX 102 by performing load modulation on the electromagneticwaves. In other words, the first communication performed by the WPCcommunication unit 205 is performed by superimposition of a signalrelated to information to be transmitted to the TX 102 onelectromagnetic waves transmitted from the power transmission antenna ofthe TX 102. The WPC communication unit 205 may communicate with the TX102 using the second communication in place of the first communication,or may communicate with the TX 102 using both of the first communicationand the second communication. In addition, when the WPC communicationunit 205 performs the second communication, the RX 101 includes anantenna different from the power receiving antenna 203. During the powerreception, the WPC communication unit 205 performs the above-describedcommunication for power reception control that is based on the WPCstandard, with the communication unit included in the TX 102.

The storage unit 206 stores a control program and also stores states ofthe RX 101 and the TX 102, for example.

The power receiving unit 207 acquires power generated in the powerreceiving antenna 203. Specifically, the power receiving unit 207acquires alternating-current power (alternating-current voltage andalternating current) generated in the power receiving antenna 203 byelectromagnetic induction caused by electromagnetic waves emitted fromthe power transmission antenna of the TX 102. Then, the power receivingunit 207 converts the alternating-current power into direct-currentpower or alternating-current power with a predetermined frequency, andoutputs power to the charging unit 208 that performs processing forcharging the battery 209. In other words, the power receiving unit 207supplies power to a load in the RX 101. The above-described value of GPindicates an amount of power guaranteed to be output from the powerreceiving unit 207. The power receiving unit 207 has the capability tosupply power for the charging unit 208 to charge the battery 209 andsupply power for outputting power of 15 watts to the charging unit 208.

The NFC unit 210 performs communication processing with anothercommunication device using the NFC function. The NFC unit 210 operatesin modes that are compliant with a specification stipulated by the NFCforum, for example. The above-described modes include, for example, acard emulation mode substituted for a role as a noncontact IC card, areader/writer mode for reading an NFC tag, and a peer-to-peer mode (P2P)mode for NFC devices directly exchanging messages. For example,electronic money payment is executable by the card emulation mode. TheNFC unit 210 includes an antenna (not illustrated), different from thepower receiving antenna 203, for performing near field communication.

FIG. 3 is a functional block diagram illustrating a configurationexample of the TX 102 according to the present exemplary embodiment. Asan example, the TX 102 includes a control unit 301, a power source unit302, a power transmission antenna 303, a WPC communication unit 304, astorage unit 305, a power transmission unit 306, and an NFC unit 307. InFIG. 3, the control unit 301, the power source unit 302, the powertransmission unit 306, the WPC communication unit 304, the storage unit305, and the NFC unit 307 are described as separate units, but aplurality of arbitrary functional blocks among these units may bemounted on the same chip.

The control unit 301 controls the entire power transmission apparatus byexecuting a control program stored in the storage unit 305, for example.In other words, the control unit 301 controls each functional unitillustrated in FIG. 3. The control unit 301 further performs controlrelated to the control of power transmission in the TX 102. The controlunit 301 may perform control for executing an application other thanwireless power transmission. The control unit 301 includes one or moreprocessors, such as a CPU(s) or a MPU(s). In addition, the control unit301 may include hardware dedicated for specific processing, such as anASIC, or an array circuit, such as an FPGA, compiled so as to executepredetermined processing. The control unit 301 causes the storage unit305 to store information to be stored during the execution of varioustypes of processing. In addition, the control unit 301 can measure atime using a timer (not illustrated).

The power source unit 302 supplies power to each functional block. Thepower source unit 302 is a commercial power source or a battery, forexample. Power supplied from the commercial power source is stored inthe battery.

The WPC communication unit 304 performs the above-described controlcommunication that is based on the WPC standard, with the RX 101. TheWPC communication unit 304 performs the first communication bymodulating electromagnetic waves output from the power transmissionantenna 303 and transferring information to the RX 101. In addition, theWPC communication unit 304 acquires information transmitted by the RX101 by demodulating the electromagnetic waves output from the powertransmission antenna 303 and modulated by the RX 101. In other words,the first communication performed by the WPC communication unit 304 isperformed by superimposition of the information on the electromagneticwaves transmitted from the power transmission antenna 303. In addition,the WPC communication unit 304 may communicate with the RX 101 using thesecond communication in place of the first communication, or maycommunicate with the RX 101 using both of the first communication andthe second communication. In addition, when the WPC communication unit304 performs the second communication, the TX 102 includes an antennadifferent from the power transmission antenna 303. During the powertransmission, the WPC communication unit 304 performs theabove-described control communication that is based on the WPC standard,with the WPC communication unit 205 included in the RX 101.

The storage unit 305 stores a control program and also stores states ofthe TX 102 and the RX 101.

The power transmission unit 306 converts direct-current power oralternating-current power input from the power source unit 302 intoalternating-current frequency power in a frequency band used forwireless power transmission, and the power transmission unit 306generates electromagnetic waves for causing the RX 101 to receive powerby inputting the alternating-current frequency power to the powertransmission antenna 303. For example, the power transmission unit 306converts direct-current voltage supplied from the power source unit 302into alternating-current voltage, using a switching circuit having ahalf-bridge or full-bridge configuration that uses a field-effecttransistor (FET). In this case, the power transmission unit 306 includesa gate driver that controls the ON/OFF of the FET.

By adjusting either one or both of voltage (power transmission voltage)and current (power transmission current) to be input to the powertransmission antenna 303, the power transmission unit 306 controls theintensity of electromagnetic waves to be output. If power transmissionvoltage or power transmission current is increased, the intensity ofelectromagnetic waves gets higher, and if power transmission voltage orpower transmission current is decreased, the intensity ofelectromagnetic waves gets lower. In addition, based on an instructionfrom the control unit 301, the power transmission unit 306 performsoutput control of alternating-current frequency power so as to start orstop power transmission from the power transmission antenna 303. Inaddition, the power transmission unit 306 has the capability to supplypower for outputting power of 15 watts to the charging unit 208 of theRX 101 that is compliant with the WPC standard.

The NFC unit 307 performs communication processing with anothercommunication device using the NFC function. The NFC unit 307 can detectthe existence of an NFC device. The NFC device includes both of an NFCtag and a device having an activated NFC function. In the NFC devicedetection performed by the NFC unit 307, it is difficult to distinguishbetween an NFC tag and a device having an activated NFC function. Thus,if an NFC device is detected by the NFC unit 307, because the NFC devicemight be an NFC tag, the control unit 301 restricts power transmissionby controlling the power transmission unit 306 to stop powertransmission or reduce power to be transmitted. The NFC unit 307includes an antenna (not illustrated), different from the powertransmission antenna 303, for performing communication related to thestandard of NFC.

(Flow of Processing)

FIG. 4 is a diagram illustrating an operation sequence of a wirelesscharging system. In the present exemplary embodiment, a user useselectronic money payment and the NFC function of the RX 101 isactivated.

First of all, the user of the RX 101 brings the RX 101 closer to thepower transmission apparatus 102 to charge the RX 101. Specifically, theuser places the RX 101 on the TX 102.

In S401, the TX 102 always performs NFC device detection processing forpreventing damages to an NFC tag. In other words, by the detectionprocessing, it is possible to detect the existence of a device having anactivated NFC function in addition to an NFC tag. The processing isperiodically executed by timer control. Thus, if the RX 101 having theactivated NFC function is brought closer to the TX 102, in S402, the TX102 detects that an NFC device exists nearby. In the detectionprocessing, the TX 102 transmits carrier waves. If the NFC device makesa response upon receipt of the carrier waves, the TX 102 detects theexistence of the NFC device. The TX 102 executes the processing aspolling processing. The detection processing may be irregularlyexecuted.

In the processing related to the power transmission and reception, firstof all, the TX 102 performs object detection processing and detectionprocessing of the RX 101. Specifically, in S403, the TX 102 repeatedlyand intermittently transmits an Analog Ping of the WPC standard via thepower transmission antenna 303. Then, the TX 102 detects a voltage valueor a current value of the power transmission antenna 303 at the time oftransmission of when the Analog Ping, and determines that an objectexists near the power transmission antenna 303, if the voltage valuefalls below a certain threshold or if the current value exceeds acertain threshold. The TX 102 then shifts to the Ping Phase.

In the Ping Phase, in S404, the TX 102 transmits a Digital Ping havinglarger power than the Analog Ping. The Digital Ping has power largeenough for activating at least the control unit 201 of the RX 101 thatexists near the power transmission antenna 303.

If the control unit 201 of the RX 101 is activated by the power (DigitalPing) received via the power receiving antenna 203, then in S405, thecontrol unit 201 recognizes that the TX 102 exists nearby. Then, if theRX 101 is detected by the TX 102 as an NFC device, then in S406, thecontrol unit 201 deactivates the NFC function of the RX 101 to preventpower transmission from being restricted.

For deactivating the NFC function, it is considered to return noresponse in the NFC device detection processing performed by the TX 102in S401, or to stop power supply to the NFC unit 210 from the powersource unit 202. In addition, a message for requesting the user todeactivate the NFC function may be displayed on the UI included in thesmartphone function processing unit 204, and the NFC function may bedeactivated in accordance with an instruction from the user. Forcharging processing, the RX 101 executes processing of preventing theuser from activating the NFC function via the UI. This is because,unless the foregoing processing is performed, the user can activate theNFC function during charging. As a result, the TX 102 detects a devicehaving an activated NFC function and restricts power transmission. Ifpower to be supplied from the TX 102 is restricted, charging of the RX101 may fail or a charging time may become longer. To avoid such asituation, UI display for preventing the NFC function from beingactivated may be presented during charging via the smartphone functionprocessing unit 204.

If the RX 101 detects the Digital Ping, then in S407, the RX 101notifies a Signal Strength Packet (received voltage value) to the TX102. Then, the RX 101 shifts to the I&C Phase. The notification of theSignal Strength Packet is communicated via the WPC communication unit205 and the WPC communication unit 304. If the TX 102 receives thenotification of the Signal Strength Packet, the TX 102 shifts to the I&CPhase.

In the I&C Phase, in S408, the RX 101 transmits an Identification (ID)Packet to the TX 102. The ID Packet includes, in addition to amanufacturer code and a basic device ID which serve as identificationinformation unique to the RX 101, an information element that canidentify the version of the WPC standard that the RX 101 is compliantwith. In S409, the RX 101 further transmits a Configuration Packet tothe TX 102. The Configuration Packet includes the following informationas capability information of the RX 101. More specifically, thecapability information includes a maximum power value that is a valuefor identifying the maximum power that can be supplied by the RX 101 tothe load, and information indicating whether a negotiation function ofthe WPC standard is included.

If the TX 102 receives these packets, the TX 102 checks whether the RX101 includes the negotiation function. If the RX 101 includes thenegotiation function, then in S410, the TX 102 transmits an ACK. Then,the TX 102 shifts to the Negotiation Phase. If the RX 101 receives theACK in S410, the RX 101 shifts to the Negotiation Phase.

In the Negotiation Phase, the TX 102 and the RX 101 perform negotiationfor determining the above-described GP. Specifically, the RX 101notifies a candidate value of GP using a Specific Request Packet. The TX102 accepts or refuses the notification. In this example, because the RX101 has the capability to output power of 15 watts to the charging unit208, in S411, the RX 101 notifies the maximum power of 15 watts as acandidate value of GP. The RX 101 waits for reception of a positiveacknowledge (ACK) or a negative acknowledge (NACK) from the TX 102.

Since the transmission of high output power can possibly damage an NFCtag, the TX 102 has a threshold of a power value at which an NFC tag isnot damaged. In this example, the threshold value is defined to be 6watts, but the threshold value is not limited to this. In S402, the TX102 that has received the Specific Request Packet detects the existenceof an NFC device using the NFC unit 307. However, because it isdifficult to determine whether the detected NFC device is an NFC tag ora device having an activated NFC function, the TX 102 determines thatthe power transmission of 15 watts can possibly damage an NFC tag if thedetected NFC device is an NFC tag. Thus, in S412, the TX 102 transmitsan NACK in response to the notification of the Specific Request Packetindicating the power value is equal to or larger than the threshold.

If the RX 101 does not receive an ACK but receives a NACK, the RX 101determines that the TX 102 has not detected that the NFC function of theRX 101 has been deactivated. Thus, in S415, the RX 101 notifies again 15watts as the value of GP.

On the other hand, if the above-described periodical NFC tag detectionprocessing is executed in S413, then in S414, the TX 102 detects that noNFC device exists near the TX 102. In other words, the detection in thismeans that the deactivation of the NFC function of the RX 101 isdetected. Thus, because the TX 102 can accept the maximum power of 15watts as a value of GP, in S416, the TX 102 returns an ACK in responseto a re-request for power transmission of 15 watts which is made by theRX 101 in S415. Then, reception of power of 15 watts is determined.

After the reception of power of 15 watts is determined, in S417, the TX102 and the RX 101 shift to the Calibration Phase. In the CalibrationPhase, the TX 102 determines a parameter required for a foreignsubstance detection function of detecting that an object other than theRX 101 exists near a power transmission antenna 303, which will not bedescribed in detail.

After that, in S418, the TX 102 and the RX 101 shift to the PowerTransfer Phase, and the RX 101 starts charging of the battery 209.During the charging, the TX 102 and the RX 101 continuously performcontrol communication that is based on the WPC standard, via the WPCcommunication unit 205 and the WPC communication unit 304.

If the RX 101 ends the charging, in S419, the RX 101 transmits an EndPower Transfer Packet to the TX 102. The TX 102 that has received thepacket stops power supply to the RX 101.

If the RX 101 ends the charging, then in S420, the RX 101 activates theNFC function of the RX 101 and brings an application that uses the NFCfunction into an effective state.

As described above, the RX 101 according to the present exemplaryembodiment deactivates the NFC function of the RX 101 by detecting theexistence of the TX 102. The RX 101 accordingly can receive appropriatepower from a power transmission apparatus equipped with an NFC tagdetection function, and the impairment of user-friendliness can beprevented.

In the present exemplary embodiment, if both of the RX 101 and an NFCtag are placed on the charging stand of the TX 102, the NFC tag isdetected by the NFC tag detection processing of the TX 102. The powertransmission is thus restricted so as not to damage the NFC tag. Even ifan NFC tag is attached to the RX 101, a similar effect can be obtained.

A method in which an RX detects the existence of a TX is not limited tothe method in which a Digital Ping is received by a WPC communicationunit. For example, a mechanical switch provided on the RX may be turnedON by a trigger provided on a charging surface of a charging stand ofthe TX when the RX is placed thereon. The RX may detect the TX bydetecting a specific physical amount (e.g., current or voltage of the RX101).

(Flow of Processing of Power Receiving Apparatus)

Next, an operation procedure of the RX 101 and the TX 102 according tothe present exemplary embodiment will be described with reference toFIGS. 5A and 5B (hereinafter collectively referred to as FIG. 5).

FIG. 5 is a flowchart illustrating an example of a flow of processingexecuted by the RX 101. The processing can be implemented by the controlunit 201 of the RX 101 executing a program read from the storage unit206, for example. At least part of the following procedure may beimplemented by hardware. The hardware in this case can be implemented,for example, by automatically generating a dedicated communicationcircuit that uses a gate array circuit, such as an FPGA, from a programfor implementing each processing operation, using a predeterminedcompiler. The processing can be executed if the power of the RX 101 isturned on, if the RX 101 is activated by power supply from the battery209 or the TX 102, or if the user of the RX 101 inputs a startinstruction of a wireless charging application. In addition, theprocessing may be started in response to another trigger.

First of all, in F501, the RX 101 determines whether a Digital Ping isreceived. If the RX 101 is activated by power (Digital Ping) receivedvia the power receiving antenna 203 (YES in F501), then in F502, thecontrol unit 201 of the RX 101 recognizes that the TX 102 exists nearby.In F503, the control unit 201 deactivates the NFC function of the RX 101for preventing the RX 101 from being detected by the TX 102 as a devicehaving an activated NFC function, and preventing power transmission frombeing restricted. A method of deactivating the NFC function is asdescribed above.

If the RX 101 detects the Digital Ping, then in F504, the RX 101notifies a Signal Strength Packet (received voltage value) to the TX102. Then, the RX 101 shifts to the I&C Phase. The notification of theSignal Strength Packet is communicated via the WPC communication unit205 and the WPC communication unit 304.

In the I&C Phase, in F505 and F506, the RX 101 transmits an ID Packetand a Configuration Packet to the TX 102.

In F507, the RX 101 determines whether an ACK is received. If the RX 101receives an ACK from the TX 102 (YES in F507), the RX 101 shifts to theNegotiation Phase. If the RX 101 does not receive an ACK (NO in F507),the RX 101 determines that the TX 102 does not include the negotiationfunction. In F522, reception of power of 5 watts is determined.

In the Negotiation Phase, the TX 102 and the RX 101 negotiate todetermine the above-described value of GP. Specifically, the RX 101notifies a candidate value of GP using a Specific Request Packet. Inthis example, because the RX 101 has the capability to output power of15 watts to the charging unit 208, in F508, the RX 101 notifies themaximum power of 15 watts as a candidate value of GP. The RX 101 waitsfor reception of a positive acknowledge (ACK) or a negative acknowledge(NACK) from the TX 102.

In F509, the RX 101 determines whether an ACK is received. If the RX 101receives an ACK as a response of the TX 102 (YES in F509), theprocessing proceeds to F521. In F521, reception of power of 15 watts isdetermined. In F510, the RX 101 determines whether a NACK is received.If the RX 101 receives neither an ACK nor a NACK (NO in F509 and NO inF510), it is determined that power cannot be received from the TX 102,and the processing is ended. In this case, in F520, the RX 101 activatesthe NFC function of the RX 101 and brings an application that uses theNFC function into an effective state. Then, the RX 101 ends theprocessing.

If the RX 101 does not receive an ACK but receives an NACK (NO in F509and YES in F510), the RX 101 determines that the TX 102 has not detectedthe deactivation of the NFC function of the RX 101. The processingproceeds to F511. In F511, the RX 101 determines whether a NACK isreceived a certain fixed number of times or more. If the RX 101 has notreceived an NACK the certain fixed number of times or more (NO in F511),then in F508, the RX 101 notifies again 15 watts as GP.

If the RX 101 has received a NACK the certain fixed number of times ormore (YES in F511), the RX 101 determines that the TX 102 cannottransmit with a power of 15 watts for some reasons. In F512, the RX 101requests power reception of 5 watts from the TX 102 as a candidate valueof GP. In F513, the RX 101 determines whether an ACK is received fromthe TX 102 as a response to the request. If the RX 101 receives an ACKfrom the TX 102 as a response to the request (YES in F513), then inF514, reception of power of 5 watts is determined. If the RX 101 doesnot receive an ACK (NO in F513), it is determined that power cannot bereceived from the TX 102, the processing is ended.

The specific reason why the TX 102 cannot transmit with a power of 15watts is that an NFC tag is detected or a device having an activated NFCfunction exists. By receiving a NACK the certain fixed number of timesor more after deactivating the NFC unit 210 of the RX 101, the RX 101can determine that the TX 102 has detected an NFC tag or a device havingan activated NFC function. Then, in F512, a transmission of power of 5watts, which is a power that does not affect an NFC tag, is determined.

After the RX 101 notifies again 15 watt as GP, if the RX 101 receives anACK (YES in F509), then in F521, a reception of power of 15 watts isdetermined.

After the reception of power of 15 watts is determined, then in F515,the RX 101 shifts to the Calibration Phase. In F516, the RX 101 shiftsto the Power Transfer Phase, and in F517, the RX 101 starts charging ofthe battery 209.

In F518, the RX 101 determines whether the charging is completed. If theRX 101 ends the charging (YES in F518), then in F519, the RX 101transmits an End Power Transfer Packet to the TX 102. If the RX 101 endsthe charging, in F520, the RX 101 activates the NFC function of the RX101 and brings an application that uses the NFC function into aneffective state.

(Flow of Power Transmission Processing of Power Transmission Apparatus)

Next, an operation procedure of power transmission processing of the TX102 according to the present exemplary embodiment will be described withreference to FIG. 8.

FIG. 8 is a flowchart illustrating an example of a flow of processingexecuted by the TX 102. The processing can be implemented by the controlunit 301 of the TX 102 executing a program read from the storage unit305, for example. At least part of the following procedure may beimplemented by hardware. The hardware in this case can be implemented,for example, by automatically generating a dedicated communicationcircuit that uses a gate array circuit, such as an FPGA, from a programfor implementing each processing operation, using a predeterminedcompiler. The processing can be executed if power of the TX 102 isturned on, if the user of the TX 102 inputs a start instruction of awireless charging application, or if the TX 102 is connected to acommercial power source and supplied with power. In addition, theprocessing may be started in response to another trigger.

In the power transmission processing, first of all, in F801, the TX 102performs object detection processing. In F802, the TX 102 performsdetection processing for detecting the RX 101. Specifically, the TX 102repeatedly and intermittently transmits an Analog Ping of the WPCstandard via the power transmission antenna 303. Then, the TX 102detects a voltage value or a current value of the power transmissionantenna 303 that is obtainable when the Analog Ping is transmitted, anddetermines that an object exists near the power transmission antenna303, if the voltage value falls below a certain threshold or if thecurrent value exceeds a certain threshold. The TX 102 accordingly shiftsto the Ping Phase. In the Ping Phase, the TX 102 transmits a DigitalPing having larger power than the Analog Ping. The Digital Ping haspower large enough for activating at least the control unit 201 of theRX 101 that exists near the power transmission antenna 303.

If the TX 102 receives the notification of the Signal Strength Packetfrom the RX 101, the TX 102 shifts to the I&C Phase.

In the I&C Phase, in F803 and F804, the TX 102 receives an ID Packet anda Configuration Packet from the RX 101. If the TX 102 receives thesepackets, then in F805, the TX 102 checks whether the RX 101 includes thenegotiation function. If the RX 101 includes the negotiation function(YES in F805), the processing proceeds to F806. In F806, the TX 102transmits an ACK. Then, the TX 102 shifts to the Negotiation Phase.

On the other hand, if the TX 102 determines that the RX 101 does notinclude the negotiation function (NO in F805), then in F819,transmission of a power of 5 watts is determined.

In the Negotiation Phase, the TX 102 and the RX 101 negotiate todetermine the above-described value of GP. The TX 102 waits fortransmission of a Specific Request Packet or a General Packet from theRX 101.

In F807, the TX 102 determines whether a General Packet is received. Ifthe TX 102 does not receive a General Packet (NO in F807) but receives aSpecific Request Packet, the processing proceeds to F809. In F809, theTX 102 determines whether power required by the Packet is equal to orlarger than a threshold. Since the transmission of high output power canpossibly damage an NFC tag, the TX 102 has a threshold of a power valueat which an NFC tag is not damaged. In this example, the threshold isdefined to be 5 watts.

If the power required by the RX 101 is smaller than the threshold (NO inF809), then in F820, the TX 102 that has received the Specific RequestPacket transmits an ACK to the RX 101. In F821, transmission of therequired power (5 watts in this case) is determined.

On the other hand, if the power required by the RX 101 is equal to orlarger than the threshold (YES in F809), then in F810, the TX 102determines whether an NFC device is detected. For the determination, theTX 102 inquires of the NFC unit 307. Since the NFC unit 307 detects anNFC device (YES in F810), the TX 102 determines that transmission ofpower of 15 watts can possibly damage an NFC tag. Thus, in F818, the TX102 transmits a NACK in response to the notification of the SpecificRequest Packet indicating the required power equal to or larger than thethreshold. Then, the TX 102 waits again for transmission of a SpecificRequest Packet or a General Packet from the RX 101.

Meanwhile, if the above-described NFC device detection processing isperiodically executed, the TX 102 stops detecting an NFC device near theTX 102 (NO in F810). The TX 102 thus can accept the maximum power of 15watts as a value of GP. In F811, the TX 102 accordingly transmits an ACKin response to a re-request for transmission of power of 15 watts fromthe RX 101. Then, in F812, power transmission of 15 watt is determined.

After the required power or the power transmission of 15 watts isdetermined, in F813, the TX 102 shifts to the Calibration Phase. Afterthat, in F814, the TX 102 shifts to the Power Transfer Phase.

In F815, the TX 102 determines whether an End Power Transfer Packet isreceived from the RX 101. If the TX 102 receives an End Power TransferPacket from the RX 101 (YES in F815), then in F817, the TX 102 stopspower transfer to the RX 101.

In the present exemplary embodiment described above, the description hasbeen given using an example case where the NFC function is activated inthe RX 101. The present exemplary embodiment is, however, not limited tothis. For example, even if the NFC function is deactivated in the RX101, a similar effect can be obtained by controlling the RX 101 so as toban the activation of the NFC function when the existence of the TX 102is detected. The control may be performed by a method in which the userdisables the activation of an NFC function using a UI, or may beperformed by a method of disabling operations on the RX 101, forexample.

In addition, in place of the processing in F511 of FIG. 5, the RX 101may perform processing for measuring a time from when an ACK is receivedin F507, and comparing the measured time and a threshold, for example.In this case, if the measured time is equal to or smaller than thethreshold, the processing in F508 may be performed again, and if themeasured time exceeds the threshold, the processing may proceed to theprocessing in F512 and subsequent operations.

In addition, the description has been given using an example in whichthe NFC device detection processing (S401) is performed by the TX 102prior to the transmission of the Analog Ping (S403), but the presentexemplary embodiment is not limited to this. For example, the NFC devicedetection processing (S401) may be performed after the transmission ofthe Analog Ping or the transmission of the Digital Ping (S404).

In the present exemplary embodiment, the description has been givenusing NFC as an example, but communication is not limited to this. Forexample, even in a case where the RX 101 includes a communicationfunction of emulating a tag that performs communication other than NFCand can be damaged by the transmission of high power, the presentexemplary embodiment can be applied.

Hereinafter, a second exemplary embodiment will be described. In thefirst exemplary embodiment, the description has been given of aconfiguration in which transmission of power of 15 watts is re-requestedeven if the RX 101 receives a NACK as a response of the TX 102 to apower transmission request of 15 watts. In this case, it can possiblytake time until the charging is started. In the present exemplaryembodiment, a configuration of shortening a time until a charging startwill be described.

Since the configurations of a wireless charging system, a powerreceiving apparatus, and a power transmission apparatus according to thepresent exemplary embodiment are similar to those in the first exemplaryembodiment, the description will be omitted. Hereinafter, an operationprocedure of an RX 101 and a TX 102 according to the present exemplaryembodiment will be described with reference to FIGS. 6 to 8. FIG. 6 is adiagram illustrating an operation sequence of the wireless chargingsystem according to the present exemplary embodiment. FIG. 7, consistingof FIGS. 7A and 7B, is a flowchart illustrating an example of a flow ofprocessing executed by the RX 101 according to the present exemplaryembodiment. FIG. 8 is a flowchart illustrating an example of a flow ofpower transmission processing executed by the TX 102 according to thepresent exemplary embodiment.

Since processing in S601 to S612 in FIG. 6 is similar to the processingin S401 to S412 of FIG. 4, the description will be omitted. In theprocessing executed by the RX 101, since processing in F701 to in F710of FIG. 7 is similar to the processing in F501 to F510 of FIG. 5, thedescription will be omitted.

If the TX 102 refuses transmission of power of 15 watts in S612 and F818(NO in F709), then in S613, the RX 101 transmits a General Packet(Capability), and in F711, the RX 101 checks the power that the TX 102can transmit.

If the TX 102 receives a General Packet (YES in F807), then in S614 andF808, the TX 102 returns an ACK as a response to the RX 101 because anNFC device is detected and the TX 102 sets 5 watts as the maximum powerthat can be transmitted. In response to the result, in S615 and F712,the RX 101 requests 5 watts from the TX 102 as a value of GP. Then, inS616 and F820, the TX 102 transmits an ACK.

In F713, the RX 101 determines whether the above-described ACK isreceived. The RX 101 receives the ACK (YES in F713), then in F714 andF812, a power reception (power transmission) of 5 watts is determined.If the negotiation of GP is ended, then in S617, F715, and F813, the TX102 and the RX 101 shift to the Calibration Phase.

After that, in S618, F716, and F814, the TX 102 and the RX 101 shift tothe Power Transfer Phase. In F717, the RX 101 starts charging of thebattery 209.

Meanwhile, if the NFC device detection processing is periodicallyexecuted in S619, in S620, the TX 102 detects that no NFC device existsnear the TX 102 (NO in F810). In other words, the deactivation of theNFC function of the RX 101 is detected.

In F718, the RX 101 determines whether the charging is completed. If thecharging is not completed (NO in F718), then in F719, the RX 101determines whether a power of 15 watts has been received. If a power of15 watts has not been received (NO in F719), the RX 101 expects that aresult obtained by the NFC device detection processing of the TX 102 hasbeen updated, and in S621 and F720, the RX 101 transmits aRe-Negotiation Request to receive larger power.

In F816, the TX 102 determines whether the Re-Negotiation Request isreceived. If the TX 102 receives the request (YES in F816), in S622 andF806, the TX 102 transmits an ACK to the RX 101.

Then, the RX 101 and the TX 102 shift to a Re-Negotiation Phase. In theRe-Negotiation Phase, the TX 102 and the RX 101 perform re-negotiationof GP. In this case, since the RX 101 has the capability to supply powerfor outputting a power of 15 watts to the charging unit 208, in S623 andF708, the RX 101 notifies again the maximum power of 15 watts as acandidate value of GP.

On the other hand, by the periodical NFC device detection processing(S619), in S620 and F810, the TX 102 detects that no NFC device existsnear the TX 102 (No in F810). Thus, the TX 102 that has received theRe-Negotiation Request and the Specific Request Packet can accept themaximum power of 15 watts as a value of GP. In other words, in S624 andF811, the TX 102 transmits an ACK in response to the re-request of powertransmission of 15 watts from the RX 101 (YES in F709). Then, in S626and S627, the RX 101 and the TX 102 shift to the Calibration Phase andthe Power Transfer Phase.

Because processing performed in S628, S629, F721, and F722 after thecompletion of charging (YES in F718) is similar to the processingperformed in S419, S420, F519, and F520 in the first exemplaryembodiment, the description will be omitted.

As described above, the RX 101 according to the present exemplaryembodiment deactivates the NFC function of the RX 101 by detecting theexistence of the TX 102. Thus, appropriate power can be received fromthe TX 102 equipped with an NFC device detection function, and theimpairment of user-friendliness can be prevented. In addition, if thefirst power transmission request of 15 watts is refused, the RX 101checks the maximum power that can be transmitted by the TX 102, andperforms negotiation using the checked maximum power. With thisconfiguration, it is possible to shorten a time until charging isstarted, as compared with the first exemplary embodiment. Then, byshifting to the Re-Negotiation Phase after the start of charging, it ispossible to shorten a charging time as compared with a case where thephase does not shift to the Re-Negotiation Phase.

Hereinafter, a third exemplary embodiment will be described. In thepresent exemplary embodiment, unlike the above-described exemplaryembodiments, the description will be given of a method in which an RX101 confirms that a TX 102 enters a state of detecting no NFC device,and the RX 101 makes a power transmission request of 15 watts.Specifically, in the present exemplary embodiment, the RX 101 transmitsa signal for inquiring of the TX 102 whether an NFC device is detected.The packet will be referred to as an NFC_Status_Request Packet in thepresent exemplary embodiment.

As a response to the packet, the TX 102 transmits at least a result(response signal) of NFC device detection processing to the RX 101.Specifically, the TX 102 transmits an ACK if an NFC device is detected,and transmits a NACK if no NFC device is detected.

Hereinafter, an operation procedure of the RX 101 and the TX 102according to the present exemplary embodiment will be described withreference to FIGS. 9 to 11. FIG. 9 is a diagram illustrating anoperation sequence of a wireless charging system according to thepresent exemplary embodiment. FIG. 10, consisting of FIGS. 10A and 10B,is a flowchart illustrating an example of a flow of processing executedby the RX 101 according to the present exemplary embodiment. FIG. 11 isa flowchart illustrating an example of a flow of power transmissionprocessing executed by the TX 102 according to the present exemplaryembodiment. Since processing in S901 to S910 and S917 to S922 of FIG. 9is the same as the processing in S401 to S410 and S415 to S420 of FIG.4, the description will be omitted. Similarly, since processing in F1001to F1007, F1013 to F1020, and F1023 of FIG. 10 is the same as theprocessing in F501 to F507, F513 to F520, and F522 of FIG. 5, thedescription will be omitted. Since processing in F1101 to F1108 andF1112 to F1119 of FIG. 11 is the same as the processing in F801 to F808and F812 to F819 of FIG. 8, the description will be also omitted.

In S910, the RX 101 receives an ACK in response to the transmittedConfiguration Packet (YES in F1007), and shifts to the NegotiationPhase. In S911 and F1008, the RX 101 transmits an NFC_Status_Request tothe TX 102. If the RX 101 does not receive an ACK from the TX 102 as aresponse signal to the request (NO in F1009) and receives a NACK in S912(YES in F1010), the following processing is performed. Morespecifically, until the RX 101 receives a NACK a predetermined number oftimes (N times) (NO in F1011), in F1008, the RX 101 transmits anNFC_Status_Request to the TX 102.

After that, if the TX 102 receives an NFC_Status_Request (YES in F1109),and if no NFC device is detected in S914 (NO in F1110) as a result ofthe NFC device detection processing (S913), the following processing isperformed. More specifically, in S916 and F1111, the TX 102 transmits anACK to the RX 101 as a response signal of the NFC_Status_Request.

If the RX 101 receives an ACK from the TX 102 in S916 (YES in F1009),the RX 101 determines that the TX 102 detects no NFC device. Then, inS917 and F1021, the RX 101 transmits a Specific Request (15 watts) tothe TX 102. If the RX 101 receives an ACK from the TX 102 as a responseto the request in S918, then in F1022, the reception of the maximumpower of 15 watts is determined.

If the TX 102 does not receive an NFC_Status_Request (NO in F11109), theprocessing equivalent to the processing in F809 and subsequent of FIG. 8is performed. Specifically, in F1120, the TX 102 determines whetherrequired power is equal to or larger than a threshold. Then, if therequired power is equal to or larger than the threshold (YES in F1120),then in F1110, the TX 102 determines whether an NFC device is detected.On the other hand, if the required power is smaller than the threshold(NO in F1120), then in F121, the TX 102 transmits an ACK to the RX 101.Then, in F1122, the transmission of required power (5 watts in thiscase) is determined.

As described above, the RX 101 according to the present exemplaryembodiment determines that the TX 102 enters a state of detecting no NFCdevice, based on the response to the NFC_Status_Request. With thisconfiguration, in accordance with the response to NFC_Status_Request, aSpecific Request (15 watt) can be transmitted at an appropriate timingand the Specific Request can be permitted. In other words, the TX 102can also perform high-output power transmission processing with respectto the RX 101 equipped with an NFC unit operating in the card emulationmode.

The response to the NFC_Status_Request needs not be an ACK or a NACK.Specifically, the response may include at least an NFC tag detectionbit, and may indicate that the TX 102 detects an NFC tag (or a devicehaving an activated NFC function), if the NFC tag detection bit is 1.The response may indicate that the TX 102 does not detect an NFC tag (ora device having an activated NFC function), if the NFC tag detection bitis 0.

A packet in a General Request defined in the WPC standard v1.2.3 may beused for the NFC_Status_Request. For example, in the General Request, aReserved Packet or a Proprietary Packet of which Packet type isundefined may be defined as an NFC_Status_Request.

A packet in a Specific Request defined in the WPC standard v1.2.3 may beused for the NFC_Status_Request. For example, in the Specific Request, aReserved Packet or a Proprietary Packet of which Packet type isundefined may be defined as an NFC_Status_Request.

In addition, the NFC_Status_Request needs not be a Specific Request or aGeneral Request as long as the packet is defined in the WPC standardv1.2.3.

Further, the NFC_Status_Request may be a packet that can be transmittedby the RX 101 in the Negotiation Phase or subsequent phases.Specifically, the NFC_Status_Request may be a packet that can betransmitted in the Negotiation Phase, the Power Transfer Phase, theCalibration Phase, or the Re-Negotiation Phase. Thus, if the TX 102receives the packet in, for example, the Ping Phase or theIdentification & Configuration phase that is not included in thesephases, power transmission or control communication for powertransmission may be stopped. Specifically, if the TX 102 receives not aSignal Strength Packet but an NFC_Status_Request in S907, the TX 102stops power transmission or control communication for powertransmission. Similarly, if the TX 102 receives an NFC_Status_Request inany of S907 to S909, the TX 102 stops power transmission or controlcommunication for power transmission. With this configuration, if apacket of an NFC_Status_Request is received in a phase other than apredetermined phase, it is possible to detect a malfunction of the RX101 and stop power transmission or control communication for powertransmission.

Other Exemplary Embodiments

Some embodiments can also be implemented by processing of supplying aprogram for implementing one or more functions of the above-describedexemplary embodiments, to a system or an apparatus via a network or astorage medium, and reading and executing the program by one or moreprocessors in a computer of the system or the apparatus. In addition,some embodiments can also be implemented by a circuit (e.g., ASIC) thatimplements one or more functions.

In addition, at least part of the processing illustrated in theflowchart in FIG. 5, 7, 8, 10, or 11 may be implemented by hardware. Inthe case of implementing the processing by hardware, for example, withuse of a predetermined compiler, the processing can be implemented byautomatically generating a dedicated communication circuit on an FPGAfrom a program for implementing each processing. In addition, similarlyto an FPGA, a gate array circuit may be formed and implemented ashardware.

Some embodiment(s) can also be realized by a computer of a system orapparatus that reads out and executes computer-executable instructions(e.g., one or more programs) recorded on a storage medium (which mayalso be referred to more fully as a ‘non-transitory computer-readablestorage medium’) to perform the functions of one or more of theabove-described embodiment(s) and/or that includes one or more circuits(e.g., application specific integrated circuit (ASIC)) for performingthe functions of one or more of the above-described embodiment(s), andby a method performed by the computer of the system or apparatus by, forexample, reading out and executing the computer-executable instructionsfrom the storage medium to perform the functions of one or more of theabove-described embodiment(s) and/or controlling the one or morecircuits to perform the functions of one or more of the above-describedembodiment(s). The computer may comprise one or more processors (e.g.,central processing unit (CPU), micro processing unit (MPU)) and mayinclude a network of separate computers or separate processors to readout and execute the computer-executable instructions. Thecomputer-executable instructions may be provided to the computer, forexample, from a network or the storage medium. The storage medium mayinclude, for example, one or more of a hard disk, a random-access memory(RAM), a read only memory (ROM), a storage of distributed computingsystems, an optical disk (such as a compact disc (CD), digital versatiledisc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memorycard, and the like.

According to some embodiments, a power receiving apparatus that canexecute communication based on a standard of NFC can appropriatelyreceive power.

While the present disclosure has described exemplary embodiments, it isto be understood that various embodiments are not limited to thedisclosed exemplary embodiments. Also, the scope of the following claimsis to be accorded the broadest interpretation so as to encompass allsuch modifications and equivalent structures and functions.

This application claims priority to Japanese Patent Application No.2018-222507, which was filed on Nov. 28, 2018 and which is herebyincorporated by reference herein in its entirety.

1. A power receiving apparatus comprising: a power receiving unitconfigured to wirelessly receive power from a power transmissionapparatus; a communication unit configured to perform communicationbased on a standard of Near Field Communication (NFC); a detection unitconfigured to detect the power transmission apparatus; and a controlunit configured to control, based on detection of the power transmissionapparatus by the detection unit, the communication unit not to performthe communication based on the standard of NFC, wherein the powerreceiving unit receives power after the control unit controls thecommunication unit not to perform the communication based on thestandard of NFC.
 2. The power receiving apparatus according to claim 1,further comprising another communication unit that is different from thecommunication unit and is configured to perform communication related topower reception control, with the power transmission apparatus, whereinthe detection unit detects the power transmission apparatus based on thecommunication related to power reception control that is performed bysaid another communication unit.
 3. The power receiving apparatusaccording to claim 2, wherein the detection unit detects the powertransmission apparatus if said another communication unit receives aDigital Ping that is based on a standard of Wireless Power Consortium,from the power transmission apparatus.
 4. The power receiving apparatusaccording to claim 1, wherein the control unit controls thecommunication unit not to respond to polling from the power transmissionapparatus that is based on the standard of NFC.
 5. The power receivingapparatus according to claim 1, further comprising a power supply unitconfigured to control power supply to the communication unit, whereinthe control unit controls the power supply unit not to supply power tothe communication unit.
 6. The power receiving apparatus according toclaim 1, further comprising: a display unit configured to display amessage for requesting deactivation of a function of the communicationunit of performing communication based on the standard of NFC, in a casewhere the power transmission apparatus is detected by the detectionunit; and a reception unit configured to receive an instruction from auser for the message displayed by the display unit, wherein, in a casewhere the reception unit receives an instruction to deactivate thefunction of performing the communication based on the standard of NFC,the control unit controls the communication unit not to perform thecommunication based on the standard of NFC.
 7. The power receivingapparatus according to claim 6, wherein, in a case where the controlunit controls the communication unit not to perform the communicationbased on the standard of NFC, the display unit displays that thecommunication based on the standard of NFC is not performable.
 8. Thepower receiving apparatus according to claim 1, further comprising adisplay unit configured to display, in a case where the control unitcontrols the communication unit not to perform the communication basedon the standard of NFC, that the communication based on the standard ofNFC is not performable.
 9. The power receiving apparatus according toclaim 1, wherein, in a case where power reception is ended, the controlunit controls the communication unit to perform the communication basedon the standard of NFC.
 10. The power receiving apparatus according toclaim 1, further comprising another communication unit that is differentfrom the communication unit and is configured to perform communicationrelated to power reception control, with the power transmissionapparatus, wherein said another communication unit transmits, to thepower transmission apparatus, a signal for inquiring whether the powertransmission apparatus has detected an object performing thecommunication based on the standard of NFC.
 11. The power receivingapparatus according to claim 10, wherein said another communication unitreceives a response signal of the power transmission apparatus to thesignal, and wherein, in a case where the control unit determines, basedon the response signal received by said another communication unit, thatthe power transmission apparatus has not detected an object performingthe communication based on the standard of NFC, the communication unittransmits a Specific Request based on a standard of Wireless PowerConsortium, to the power transmission apparatus.
 12. The power receivingapparatus according to claim 1, wherein the communication unit performsthe communication based on the standard of NFC, in a card emulationmode.
 13. A control method performed by a power receiving apparatusincluding a power receiving unit configured to wirelessly receive powerfrom a power transmission apparatus, and a communication unit configuredto perform communication based on a standard of Near Field Communication(NFC), the control method comprising: detecting the power transmissionapparatus; controlling, based on detection of the power transmissionapparatus, the communication unit not to perform the communication basedon the standard of NFC; and receiving power by the power receiving unitafter the communication unit is controlled not to perform thecommunication based on the standard of NFC.
 14. The control methodaccording to claim 13, wherein the power receiving apparatus furtherincludes another communication unit that is different from thecommunication unit and is configured to perform communication related topower reception control, with the power transmission apparatus, andwherein the power transmission apparatus is detected based oncommunication performed by said another communication unit.
 15. Thecontrol method according to claim 13, wherein the communication unit iscontrolled not to respond to polling from the power transmissionapparatus that is based on the standard of NFC.
 16. The control methodaccording to claim 13, wherein the power receiving apparatus furtherincludes a power supply unit configured to control power supply to thecommunication unit, and wherein the power supply unit is controlled notto supply power to the communication unit.
 17. A non-transitory computerreadable storage medium storing a program which causes a computer toperform a control method performed by a power receiving apparatusincluding a power receiving unit configured to wirelessly receive powerfrom a power transmission apparatus, and a communication unit configuredto perform communication based on a standard of Near Field Communication(NFC), the control method comprising: detecting the power transmissionapparatus; controlling, based on detection of the power transmissionapparatus, the communication unit not to perform the communication basedon the standard of NFC; and receiving power by the power receiving unitafter the communication unit is controlled not to perform thecommunication based on the standard of NFC.